Detroit scored an unearned run in the eighth inning when right fielder Charlie Moore misplayed Lou Whitaker's long fly ball and the Tigers de-feated the Brewers, 2-1, last night to split the dou-bleheader in Milwaukee.

Cecil Cooper hit a two-run homer and Moose Haas and Pete Ladd pitched a six-hitter as the Brewers won the first game, 2-1.

The Tigers won the nightcap despite being out-hit, 10-4. With the score 1-1 in the eighth, Chet Lemon and Wayne Krenchicki singled off reliever Jim Slaton (12-6). Lemon scored from second when Moore, on the warning track, appeared to lose Whi-taker's fly in the lights.

It was the first appearance for Haas (13-3) since Aug. 26, when it was decided that he needed rest because of a tired arm. It marked the first time since 1980 that Haas, who struck out three and walked two in eight innings, has won 13 games in a season.

The victory also was Haas' sixth straight over the Tigers; he has a 9-4 lifetime record against them. Ladd pitched the ninth for his 20th save.

Jim Gantner singled in the Milwaukee fourth, then Cooper hit his 27th homer, off Jack Morris (18-10), and raised his RBI total to 113.

Detroit's only run came on Larry Herndon's homer, his 18th, in the eighth.